Horse Costume Help

I don't know how many artistic people are on this forum but here it goes. My church is doing a haunted hay ride this year and I volunteered to be the Headless Horsemen( women). The horse I am going to ride is my 21 year old Leopard Appaloosa. I want to use a face plate I used on him years ago at a Halloween parade, it looks similar to one worn by a knight's horse. This one has three ( not sharp) spikes on it and I think it would help add a creepy flair to the whole thing. To give you an idea of what Renegade looks like think Dalmatian in horse form. So I got measurements off of him to make a cover for him, again like one worn by a medieval knights horse, only in black. Otherwise it would be all to easy to see him coming. Any other ideas of what I could add to this costume?

Not sure where you'd get them or how a horse would take to dangly things on him, but maybe some mannequin heads in a mesh bag somewhere?

That sounds like a cool idea. My horse wodn't care, it takes a lot to frazzle his nerves